Beam welding apparatus and methods

Abstract

An apparatus and method may be used for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side. The apparatus has a welding beam generator. The apparatus reduces a pressure along the inboard side of the panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion. The apparatus has locates, based on said deflection, at least one of said first portion or said second portion.

1. An apparatus for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side, the apparatus comprising:
 means for generating a welding beam; 
 means for reducing a pressure along the inboard side of the panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion; and 
 means for locating based on said deflection at least one of said first portion or said second portion. 
 
   
   
     2. The apparatus of  claim 1  further comprising:
 means for directing the welding beam to said second portion responsive to said locating. 
 
   
   
     3. The apparatus of  claim 1  wherein:
 the means for locating comprises a laser holography apparatus. 
 
   
   
     4. The apparatus of  claim 1  wherein:
 the means for locating comprises: a laser holography apparatus; and a video display displaying a holography fringe pattern from said laser holography apparatus. 
 
   
   
     5. The apparatus of  claim 1  wherein:
 the means for generating the welding beam comprises at least one of a laser generator and an electron gun. 
 
   
   
     6. The apparatus of  claim 1  wherein:
 the means for reducing the pressure comprise a plenum element welded to the first and second elements. 
 
   
   
     7. An apparatus for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side, the apparatus comprising:
 a fixture dimensioned to engage and hold an assembly of the first panel and second panel; 
 a welding beam generator positioned to direct a welding beam to the assembly; 
 a pump coupled to the fixture so as to reduce a pressure along the inboard side of the first panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion; 
 a first laser generator positioned to direct a first laser beam to the outboard side of the first panel; and 
 a detector positioned to detect reflection of the first laser beam. 
 
   
   
     8. The apparatus of  claim 7  further comprising:
 a controller coupled to the detector and the welding beam generator and configured to direct the welding beam to said second portion responsive to detection of said reflection. 
 
   
   
     9. The apparatus of  claim 7  wherein:
 the welding beam generator comprises a second laser generator. 
 
   
   
     10. The apparatus of  claim 7  wherein:
 the welding beam generator comprises an electron beam generator. 
 
   
   
     11. The apparatus of  claim 7  wherein:
 the welding beam generator comprises an actuator for traversing the welding beam across the first panel. 
 
   
   
     12. The apparatus of  claim 7  in combination with the first panel and second panel and wherein:
 the first panel is an essentially flat sheet; and 
 the second panel has an essentially flat first side and a second side having a plurality of parallel ribs. 
 
   
   
     13. A method for welding a first panel to a second panel, the first panel having an inboard side partially contacting the second panel and an opposite outboard side, the method comprising:
 reducing a pressure along the inboard side of the first panel relative to an adjacent pressure along the outboard side so as to produce inward deflection of the first panel along a first portion of the first panel not contacting the second panel relative to a second portion; 
 based on said deflection, locating at least one of said first portion and said second portion; and 
 responsive to said locating, directing a welding beam to said second portion. 
 
   
   
     14. The method of  claim 13  wherein:
 the locating comprises laser holography. 
 
   
   
     15. The method of  claim 13  wherein:
 the directing causes the welding beam to weld the first panel to the second panel along a plurality of parallel ribs of the second panel. 
 
   
   
     16. The method of  claim 13  further comprising:
 welding at least one sacrificial sealing element to the first and second panels. 
 
   
   
     17. The method of  claim 16  wherein the sealing element is an annular plenum element. 
   
   
     18. The method of  claim 13  wherein:
 the first and second panels essentially form a body of revolution about a longitudinal axis; and 
 the first and second panels are progressively incrementally rotated essentially about the longitudinal axis to permit successive welding of individual locations forming the first portion. 
 
   
   
     19. The method of  claim 18  wherein:
 the individual locations are associated with longitudinal ribs of the second panel and the welding comprises essentially longitudinally translating the first and second panels relative to the welding beam. 
 
   
   
     20. The method of  claim 19  wherein:
 the welding further comprises dynamically correcting for error in rib alignment by rotating the first and second panels essentially about the longitudinal axis. 
 
   
   
     21. The method of  claim 13  further comprising:
 milling a plurality of channels in the second panel to leave ribs.